1. Field of the Invention
This invention relates to automated glass cooler entrance doors. More particularly, this invention relates to walk-in commercial refrigeration coolers having entrance glass doors.
2. Description of the Background Art
Presently, display refrigerators and freezers are commonly used in retail stores such as grocery and convenience stores for refrigerating merchandise such as beverages behind glass doors allowing the discriminating shopper to view the merchandise while shopping. Once the selection is made, the shopper may then open the glass door, reach-in and remove the product from the refrigerator or freezer.
Another method to merchandise cold beverages allows the customer to walk into the cooler to make a product selection. Walk-in coolers require the doors to be full-view glass not only for customer appeal but also to allow store personnel to monitor the interior of the cooler to prevent shoplifting.
Hinged manual glass entrance doors that swing open are generally available throughout the industry. Manual swing doors are undesirable, however, because the customer is preferably carrying a large amount of product such as a case of beer and cannot conveniently open the doors to exit the cooler. Hence, it is now commonplace for walk-in coolers to be fitted with automatic sliding glass doors that automatically open and close as a customer approaches the doors from the outside during ingress and, conversely, to also automatically open and close during customer egress. For example, U.S. Pat. Nos. 6,525,659 and 6,225,904, the disclosures of which are incorporated by reference herein, teach the use of motion and presence sensors to sense the ingress or egress of a customer and to control the energization, acceleration and deceleration of the sliding doors during opening and closing.
It is well recognized that conventional storefront automated entrance doors cannot be used for cooler entrance doors because the temperature difference between the store and the cooler is so significant that condensation forms exteriorly on the doors and on the sliding glass door drive components located inside the header above the doors. Not only does condensation present an unsightly appearance to the customer, it also presents a safety hazard to customers as the condensation puddles on the floor and leads to premature failure of the internal drive mechanism.
More particularly, it is recognized that storefront automated entrance doors perform satisfactorily for store entrance because generally there is little temperature difference from one side of the door to the other. A double set of automated doors, including an airlock, may even be employed in northern climates. During winter months, the indoor relative humidity is relatively low, thereby reducing the amount of condensation and allowing the use of the automated doors. However, using a double set of automated entrance doors for a walk-in cooler requires too much valuable floor space and is cost prohibitive. Even if a double set of doors are used, condensation would nevertheless form on the doors and drive mechanism during higher relative humidity conditions in summer.
Therefore, it is an object of this invention to provide an improvement which overcomes the aforementioned inadequacies of the prior art devices and provides an improvement which is a significant contribution to the advancement of the commercial walk-in cooler art.
Another object of the invention is to provide a way to employ automated doors for walk-in coolers in such a manner that condensation on the doors and drive mechanism is minimized.
The foregoing has outlined some of the pertinent objects of the invention. These objects should be construed to be merely illustrative of some of the more prominent features and applications of the intended invention. Many other beneficial results can be attained by applying the disclosed invention in a different manner or modifying the invention within the scope of the disclosure. Accordingly, other objects and a fuller understanding of the invention may be had by referring to the summary of the invention and the detailed description of the preferred embodiment in addition to the scope of the invention defined by the claims taken in conjunction with the accompanying drawings.